In recent years, various printer manufacturers have designed methods for users to access internal features of their printers. Typical of these features are the ability to set margins, specify type fonts, do underlining, print graphics images, set line spacing, and establish a desired page orientation. These features are typically accessed by transmitting certain predefined character sequences to the printer, and taken together these defined character sequences constitute a "printer language" as this term is used herein.
Various printer languages of the type described above have been developed to control the format of the text and graphics output from printers such as electrophotographic or laser printers. In the past, if a user needed only high speed, high efficiency text printing capability, then he or she might prefer to use the printer language well known in the art as the Printer Command Language (PCL) developed by the Hewlett Packard Company of Palo Alto, Calif. to define a standard for printer features and feature access by software applications. Conversely, if a user needed a more graphic oriented output print capability, he or she might at one time have chosen the well known PostScript printer language made available by Adobe Systems Incorporated of Mountain View, Calif. as a device-independent page description language.
In the field of computer-to-printer network systems designed to provide a user with the above printer language selection capability, it has been a common practice to interconnect a plurality of personal computers through a central print serving station, known as a print server, into a plurality of available printers having different printer languages operational therein. Upon receipt of a printer selection signal from a computer and based upon the command language in which the computer software operates, the print server is operative to match and connect the printer and computer so that they operate in the same printer and computer command language.
As an example, some of the above plurality of personal computers may be operational on software such as the well known MicroSoft Word (MS Word) software developed by MicroSoft Incorporated of Richland, Wash. Computers operating with MS Word software may, for example, be operated in the above well known PostScript command language to thereby cause the printers to which they are connected to generate text and graphics in the well known PostScript text and graphics format. Thus, it is essential that the print server operate to interconnect these personal computers operating on MS Word software to corresponding printers which are also operating in the PostScript printer language. Examples of personal computers which operate on the PostScript command language are those provided by Apple Computer, Inc. and International Business Machines.
Conversely, a computer user operating his or her computer with WordPerfect operating with the well known Printer Command Language or PCL language developed by the Hewlett Packard Company needs to have this computer connected and matched to a printer operating in this same PCL language. In this case, it may be preferable for the print server to interconnect these latter computers to one of the Hewlett Packard LaserJet Series of electrophotographic printers which operate in response to this well known PCL printer command language.
The above software command and printer language matching requirement is also present in the situation where a single personal computer is operable with different types of software having different command languages and is connected by multiple wires to a single printer. In this application and connection, the single printer is usually operative with the use of one or more command language conversion cards in order to function in more than one printer control language. Data in one command language received from a computer is converted in these language conversion cards to a different printer language before being applied to the laser scan electronics in the operation of the connected electrophotographic printer.
However, in either of the above types of network systems, the personal computer user is currently required to make a necessary keyboard (keycap) or other equivalent selection in order to ensure that the correct electrical connections are made between the personal computer to either a desired printer or to a correct command language conversion card terminal within a single printer to properly match the command language of the personal computer software to a printer operating with that same corresponding printer language.
The obvious disadvantage with the above requirement for proper keycap selection not only involves an additional computer keyboard operation for the user, but a failure to execute this proper and necessary keyboard operation means that the improperly selected printer or command language conversion card will be totally inoperative when connected to the incorrect and improperly connected computer command language.